Update many PCs in the same time ?

EdTittel said:

It's supposed to be implemented some time before the Creator's Update appears in April of this year. Hasn't materialized yet, but is coming "real soon now," to parrot Larry Niven's famous phrase of unfulfilled promises.
HTH,
--Ed--

That's my understanding too. There was a blog post with one of the Insider versions around September-ish (? I think?) which said the feature to get updates from other local computers had been enabled for the first time in that Insider build. I don't think it's made it to the non-Insider builds yet.

Meanwhile, the OP could manually download the relevant Cumulative Update KBxxxxxx from the Microsoft Update Catalog and then apply the update on individual machines. I'm not sure if this will save bandwidth unless you have a lot of computers, as you'd be downloading the whole cumulative update with all patches back to the main release, when I think that Windows Update, left to its own devices, will just download the specific bits which computer needs.

But it does give some control over the process.

Of course there are other updates too, but the Cumulative Updates will cover most of the crucial and time-consuming stuff, and Windows Update will probably cover the rest fairly quickly.

Edit: I found the blog post I was thinking of:
Announcing Windows 10 Insider Preview Build 14915 for PC and Mobile - Windows Experience BlogWindows Experience Blog

It looks like my memory wasn't quite correct - it does suggest that Windows 10 should have been downloading updates across the local network since the '1511' version, although obviously that doesn't chime with the experience of folks here.